The present invention is generally directed towards a socket for making electrical connections to the pins on the neck of a cathode ray tube, and more particularly to an improved spark gap structure for such a socket.
As well known, during the operation of a cathode ray tube, sparking or arc-over within such tubes often results. The sparking or arc-over usually occurs within the cathode ray tube gun structures and is generally caused by the high voltages applied to the elements of the guns. Such arcing results in surge voltages and currents being applied to the external pins of a cathode ray tube which, if of high enough voltage or current, can sometimes cause serious damage to the electronic circuitry connected thereto.
In the past, the problem of cathode ray tube arcing was not as serious as it is now because, in the case of a television receiver for example, the television circuitry external to the cathode ray tube comprised vacuum tubes. Vacuum tubes generally are capable of withstanding momentary voltage or current surges without being seriously damaged or destroyed. However, such is not the case with solid-stage circuitry.
In recent years, solid-state circuitry for television receivers has become increasingly popular. The popularity of solid-state television receivers generally has been due to their reduced power consumption as compared to their tube counterparts, longer useful life, greater reliability, and their "instant on" operation. However, solid-state components such as transistors are more susceptible to being damaged by voltage and current surges than are tubes. As a result, it is often desirable to provide some means for preventing the solid-state components from the surge voltages and currents resulting from cathode ray tube arcing.
In providing such protection, resort was had to spark gaps for dissipating surge voltages and currents to ground potential which resulted from the aforementioned arcing within cathode ray tubes. For example, spark gaps within the cathode ray tubes themselves were attempted but eventually discarded for being too costly. Eventually, it was found that spark gaps could be incorporated within the cathode ray tube sockets which connect the pins thereof to the external circuitry. While such sockets have proven to be both generally effective and commercially feasible, there remains substantial room for improvement.
For example, in order to minimize the production costs of tube sockets incorporating spark gaps, the electrodes of the spark gaps have been rather crudely stamped or formed on a high volume basis resulting in random sharp edges on the electrodes. These sharp edges, in many instances, have promoted arcing themselves and, because of their random nature, have not provided consistent arc-over voltage protection. Furthermore, cathode ray tube sockets having such spark gaps have been somewhat complex, comprising a plurality of small component parts to form the spark gaps. As a result, the materials, molding, and assembly costs of such sockets, even on a mass production basis, have been inordinately high.
It is therefore a general object of the present invention to provide a new and improved socket for making electrical connection to the pins of a cathode ray tube.
It is a further object of the present invention to provide a new and improved socket for making electrical connections to the pins on the neck of a cathode ray tube which includes an improved spark gap structure for protecting external solid-state circuitry or the like.
It is a more particular object of the present invention to provide such a socket which minimizes the number of component parts required in forming the spark gaps to the end of reducing the cost of manufacturing the sockets.
It is a more particular object of the present invention to provide such a socket wherein the spark gaps are so formed that reliable and consistent surge voltage and current protection is afforded to the external circuitry connected thereto.